CROSS-ANTIGENICITY AMONG SIX SPECIES OF DUST MITES AND HOUSE DUST ANTIGENS

Body and excreta of Dermatophagoides farinae were found to be an important allergen in house dust. However, house dust contained more than 35 species of mites. The major mites in house dust are Glycyphaginae and D. pteronyssinus, which make up 31.8 per cent and 27.2 per cent, respectively. D. farinae comprises only 4 per cent of the total mites, as an average, in house dust in Japan. Consequently antigenic relationships between house dust and 6 species of mites, including D. farinae, were studied by the method of the skin testing and the in vitro neutralization of skin-sensitizing antibody. It was found that D. farinae was most closely related to house dust antigen in comparison with 5 other species of mites: Chortoglyphus arcuatus, Blomia sp., Aleuroglyphus ovatus, Suidasia nesbitti, and Tyrophagus putrescentiae. Cross-antigenicity was found among these mites although this was not complete, and it was considered that each species of mite had its own characteristic antigen. Moreover, the antigenicity of D. farinae was quite potent, and D. farinae appeared to possess the major common antigen among these species of mites. Consequently the existence of identical antigenicity between house dust and D. farinae was not surprising even though D. farinae constituted only a few per cent of the mites in house dust in number. D. farinae and C. arcuatus were more potent in skin reactivity in comparison with other species of mites, but cross-antigenicity between these 2 species of mites was not as close as that between the other species. The bodies of mites had identical antigenicity with the excreta. © 1969.